Novel reactions of trifluoromethyl group in heterocycles

TetrahedronLetters No.45, pp. j901-j902,1970. PergamonPress. Printed in Great Britain.

NOVEL REACTIONS

Yoshiro Kobayashi,

OF TRIFLUOROMETHYL

Itsumaro Kumadaki,

GROUP IN HETEROCYCLES

Shigeru Taguchi, and Yuji Hansawa

Tokyo College of Pharmacy. Shinjuku-ku,

Tokyo, Japan

(Receivedin Japan 22 July 1970; receivedin UK for publication26 August 1970)

Trifluoromethyl

group has often been refferred as a pseudohalogen

there is no report of its substitution carbon-carbon cycles.

bond.

by a nucleophile

a fission of

Now, we report a novel reaction of trifluoromethyl

2-(Trifluoromethyl)quinoline

nia to give 2-aminoquinoline

Similarly,

this reaction proceeds

and 1-(trifluoromethyl)isoquinoline

and 1-aminoisoquinoline

to give

in 88% and 57% yields, respectively.

Then this reaction was applied to 3- and 4-(trifluoromethyl)quinoline. (Trifluoromethyl)quinoline

hetero-

reacts with sodium amide in liquid ammo-

in 69.5% yield.

with 2-(trifluoromethyl)pyridine P-aminopyridine

involving

(11, but

gave 3-cyanoquinoline

3-

and 4-amino-3-cyanoquinoline

in 20% and 2.5% yields, respectively. 4-(Trifluoromethyl)quinoline o-(formylamino)phenylethyne However, these reactions heterocycles, is recovered

gave 2-amino-4-(trifluoromethyl)quinoline

in 3% and 9% yields, respectively. of trifluoromethyl

since trifluoromethylbenzene quantitatively.

of these reactions.

group are characteristic

of the

does not undergo this reaction and

The following is the assumption of the mechanisms

In these mechanisms,

behavior of the trifluommethyl

differs according to its position in the heterocycle; positions were liberated

and

these in the 2- and 4-

in the same manner as halogens.

3901

group

3902

No.45

cl-

0 N

-CF3@

NH20

NH 2

cF3

All the products were identified point with the authentic

by IR spectra, NMR, and admixture melting

samples.

REFERENCE 1. W.A.Sheppard and C.M.Shirts, Inc., New York (1969).

Organic Fluorine Chemistry, p. 62, W.A.Benjamin,